1. Field of the Invention
The present invention relates to an improvement in a brushing apparatus used for sleeping grains of sand, clay, etc. spread on the lawn of the putting greens in a golf course into previously formed core holes or alternatively for use in cleaning or waxing floors of buildings.
2. Description of the Related Art
Conventionally, the lawn of the putting greens in golf courses, for example, is cut at rhizomes thereof, in which cores are drawn to provide air to the roots of the lawn. After the cores are drawn, grains of sand, clay, etc. are swept into the core holes while brushes, disposed in more than two rows arranged in the direction that a vehicle travels, rub the grains of sand, clay, etc. while the brushes travel in a forward direction.
When the above-mentioned work was carried out in the past, sand grains etc. were spread on the lawn by a grain sprinkler, and the grains were rubbed to the bases of the lawn, which operation was manually performed with rake-like brushes.
It was recognized that the above-mentioned work requires a lot of manhours and can be inefficient. Therefore, it was suggested that such rake-like brushes be attached to a vehicle installed with a roller to carry out brushing for rubbing the sand grains etc. into the bases of the lawn and smoothing the surface of the lawn by the roller.
However, since the putting green in golf courses is not smooth or flat, and the growth and density of the lawn are different, the work to rub the grains to the bases of the lawn should be performed in consideration of the condition of the lawn. Further, the putting green is not a complete plane but is uneven on account of slopes, undulations, including upheavals and depressions, and it is impossible to level the putting green by a simple means.
In consideration of the above conditions, the present applicant developed a brushing device disclosed in Japanese Utility Model Application No. Heisei 3-53141, and a brushing apparatus disclosed in Japanese Utility Model Application No. Showa 59-70438, in which a first brush frame, to which a brush is attached on the under-side thereof, is connected to a second brush frame such that the second frame is vertically rotatable.
When the quantity of the grains is large, the brushes for rubbing the grains into the core holes yield to warp backward. On the other hand, when the quantity is small, the sand grains etc. moved by the brushes is small in quantity and the warpage experienced by the brushes is reduced; In either case, the quantity of the sand grains which is swept into the core holes is insufficient to completely fill the holes, thereby creating an annoyance to the players.
in addition, the grains moved by the brushes in such apparatus is swept into the core holes in such a manner that the grains are swept thereinto from a rearward direction in relation to the travel of the vehicle. As a result, the grains can collect one-sidedly to a rearward portion of the core holes in relation to the traveling direction and it is impossible to evenly fill the whole core hole space.
Further, if the position of the brush does not change in accordance with slopes, undulations including upheavals and depressions which are commonly provided on putting greens, the brush contact with the green face can be too strong or too weak depending on the locations. In other words, there is a problem that the sand grains are not evenly swepted into the core holes.
Then, the above-mentioned slopes and unevennesses of the green cause the brush to yield to warp rearwardly with respect to the traveling of the vehicle. As a result, the quantity of the grains moved in the direction that the vehicle travels is insufficient, resulting in insufficient quantity of the grains being placed in the core holes.